The genus is characterized by biatorine (rarely zeorine), yellow to orange or brown apothecia with a paraplectenchymatous excipulum, partially amyloid hymenium (I+ blue then quickly sordid green then red-brown), thin-walled unitunicate asci, and 1-septate or rarely non-septate ascospores.

[6] Similar genera include Malcolmiella, which differs mainly by having amyloid asci with a thickened tholus and non-septate, usually longer and broader ascospores with an ornamented perispore; Absconditella, which has a chlorococcoid photobiont and non-amyloid asci; and Cryptodiscus, which has Gloeocystis as photobiont, amyloid asci with a thickened apex and non-septate paraphyses.

Examples include thallus growth,[7][8] apothecial development,[9] ultrastructure,[10] photobiont and resynthesis in culture,[11][6] and photosynthesis.

[14] Johannes Müller Argoviensis even used his erroneous interpretation of the thallus organization of filamentous Coenogonium to oppose Simon Schwendener's theory of the symbiotic nature of lichens.

[15] The genus is well known in continental areas that border the Caribbean, such as Florida and Costa Rica.